Polarized magneto signal device



April 3, 1956 w. HATTON 2,740,956

FOLARIZED MAGNETO SIGNAL DEVICE Filed Oct. 19, 195] 2 Sheets-Shea?l 1 FIG l I K? a [Z ;igiii; i

ATTORNEY April 3, 1956 w. HATTON POLARIZED MAGNET@ SIGNAL DEVICE 2 Sheets-Sheet 2 Filed OC'C. 19, 195] FIG. 8.

FIG. 7.

FIG. 6.

FIG. IO.

FIG. 9.

INVENTOR. IA/HaTTaN BY Wl ma ATTORNEY United States Patent O POLARIZED MAGNET() SIGNAL DEVICE William Hatton, South Orange, N. J., assignor to International Telephone and Telegraph Corporation, a corporation of Maryland Application October 19, 1951, Serial No. 252,075

8 Claims. (Cl. 340-373) This invention relates to an improved magneto signal device particularly adapted for use with telephone switchboard equipment.

A primary object of the invention resides in the provision of an improved magneto signal device of extreme sensitivity and capable of either mechanical or electrical restoration.

Another object is to provide an improved magneto signaling device which is capable of electrical or manual restoration, and permits the signal to remain connected across the line for use not only as a call signal, but as a supervisory signal, as, for example, in telephone systems employing common battery supervision.

An additional object is therefore to provide an improved magneto signal apparatus for indicating signals of one polarity, including a visual indicator which remains in the indicating position after termination of the signal until restored either electrically by a signal of opposite polarity or by mechanical means.

A further object is to provide in an electrically restorable magneto signal device, an improved manually operable linkage for the restoration of the device to a nonindicating position.

Another object resides in incorporating in a magneto signal device an auxiliary switch, operable in response to a signal of a given polarity, for control of an auxiliary intelligence-indicating system such, for example, as a night alarm signal.

The aboveanentioned and other features and objects of this invention and the manner of attaining them will become more apparent and the invention itself will be best understood, by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:

Fig. l illustrates a simple magneto signal apparatus incoporating the principles of the present invention.

Figs. 2 through 5 illustrate a preferred embodiment of the invention as reduced to commercial production.

Figs. 6, 7, 8 and l0 are fragmentary views of portions of the apparatus shown in Fig. l, to be used in the description of operation.

Fig. 9 illustrates the device of Figs. 6 through 8 and including a switch for control of an auxiliary warning system.

Fig. 1l shows in perspective an armature mounted cam as employed in the device of Figs. 2 through 5.

Referring to Fig. l, a device illustrating the basic principles of the invention includes generally an electromagnet, generically designated 10, including core 11 of material having low magnetic permeability characteristics, and a suitable electrical winding 12, partially enclosing core 11. Coil may be excited by application of rectied alternating current. Suitable alternating current, from a source not shown, may be connected to line 15, rectifier 16 being provided to convert the alternating current into pulsating direct current. The left end of core 11, as shown in Fig. l, has attached thereto a return pole piece 18, of material similar to that of core 11, to extend rice back along coil 10 in spaced relation thereto and beyond the opposite or free end of core 11, preferably to terminate in a diagonally raised portion 20. A permanent magnet type armature 21, pivoted at 22, for operation through an arc extending'from the end portion 20 of return pole piece 18 to the free end of core 11, has Xed thereto a visual indicating element 24 which may be a semi-spherical button-like indicator mounted on a suitable support illustrated at 26. Pivoting of magnet 21 from the position shown to a position of substantial alignment with core 11, as later described, results in the pivoting of indicator element 24 from the retractive position shown in respect to a viewing window 28 in suitable housing 29, to a viewing position, not shown, in alignment with window 28.

Fig. 6 illustrates the position of armature 21 with no current flowing in line 15. In this condition, the permanent magnet armature 21, the north pole ot which depends with the south pole at the pivotal position as shown, is attracted to end 20 of return pole piece 18. Since return pole piece 18, like core 11, is of a material offering small residual magnetism, the adjacent north pole of the fixed magnet 21 induces a south pole S in portion 20 thereof to the extent that armature 21 is suiiiciently attracted to end portion 20 to render the device insensitive to shock and vibration, with indicator 24 held in a retracted or concealed position in respect to window 28.

Referring to Fig. 7, when current is applied to line 15 with rectifier 16 so connected in the circuit to insure direct current of proper polarity, the free end of core 11 is magnetized as a south pole S with the return pole piece 18 rendered a north pole N at its terminus 20. Assuming, as in Fig. 6, that xed magnet 21 is mounted with the north pole depending and the south pole at the pivotal position, a repelling action between the adjacent north pole of magnet 21 and the north pole of portion 20, coupled with the attraction between the depending end of magnet 21 and the south pole induced in the free end of core 11 will result in a rapid pivoting of magnet 21 to the position shown in Fig. 8, with subsequent position of indicating element 24 in the viewing position in respect to Window 28. When the line or signal current is terminated, with magnet 21 in the position of Fig. 8, the north pole thereof induces a south pole S in the adjacent end of core 11, to replace the south pole which was previously induced therein by the line current, hence there is continued attraction between magnet 21 and core 11 sutiicient to retain the visual indicator 24 in a position aligned with window 28 during normal shock or vibration.

vAs shown in Figs. 1 and 6 through l0, the free end of core 11 is bevelled at 27, the lower end of armature 21 being bevelled at 39 for complementary abutment therebetween under conditions illustrated in Fig. 8. As best shown in Figs. 6 and 7, the lower end of armature 21 is also provided with an opposite taper 38, the angularity of which corresponds to the taper of raised end portion 20 of return pole 18. As shown in Figs. 6 and 7, no actual contact is made between the armature and pole piece with the armature in a vertical position, but momentary contact occurs therebetween during return of the armature 21 from the position of Fig. 8 to that of Fig. 7, pole portion 2i) serving as a stop member to prevent overshoot and oscillation of armature 21. Under certain conditions it may be desirable to either position core 11 out of the path of movement of armature 21, or to eliminate the stopping action of pole portion 20.

Figs. 2 through 5 illustrate another adaptation of the invention which further simplities the structure and permits an even further reduction in spacial requirements. The device illustrated has been found particularly elective in meeting the demand for an inexpensive and highly compact magneto signal including the feature of both electrical and mechanical restoration, and for this reason, Figs. 2 through 5 maybe considered a preferred ernbodiment of inventive principles. As best shown in Fig. 3 (which figure is partly in section), coil 110 ,includes core 111 about which is applied -a conventional winding 112, `the details being omitted, a free end of core 111 extending beyond the winding 112 as shown. The .end lof core 111 is preferably, although not necessarily, slotted at to provide pole portions 31 and 32 lfor increased ,flux density. Pole portion 31 is formed by tapering the cylindrical Vcore 111 as shownat 33. Pole portion 32 is preferably bevelled .at 34 to provide a stop surface for a purpose described below.

The unitary assembly shown is :adapted .forretractable disposition within a ,complementary holder normally disposed in a whoripontal plane, although the device will operate in all positions.v in compliance with conventional practice, core 111 and all electrically conductive portions o f the device, with the ,exception of winding 112, aregrounded. Toeifect this end, a skeleton type mounting frame .45 serves the dual function of presenting aligned surfaces on all sides of a rectangle, as viewed in cross section, for `sliding Contact with a suitable holder, while also providing a terminal strip to .electrically connect the left or aft end of the core, Fig. 2, with the metallic structure located at the right or vforward end, `as described below. Frame includes a forward platform 47, of cross-sectional U configuration shown in Fig. 4 to provide support for a slidably mounted push rod 4S and also to provide electrically contacting pressed t engagement with a pair of spaced bracket arms 56 and 51, later described. Frame 4 5 is of known design, with the opposite end being apertured for mounting to a threaded extension 61 of core 111, portion 60 being held in clamped engagement therewith between washer 63 and nut 64. lt is readily seen that the configuration of frame 45 is such as to present `surfaces on four sides of areetangle as viewed in cross-section. Frame 45 provides contacting surfaces for ythe maintenance of good electrical contact with an associated holder, the ycomplementary surfaces of which are grounded, while providing necessary support for the mounting ,of push rod 4 8 and contributing to the rigidity `of the device as a unitary structure.

Referring to the forward `end of coil 110, anelectrically insulating support member 40 is attached thereto in a suitable manner, preferably by application in pressed t engagement with the expo-sed end of core 111 to be retained in abutment with the coil end. Member 4 0 is of rectangular conguration to provide support lfor spaced brackets and 5 1, retained .clamped on opposite sides thereof by a pair of clamp screws 4 1 which extend through member llt) above and below core 111 to etiect clamped engagement of the brackets on opposite sides of member 40. Brackets Si) and 51 lead from an integral base lportion 65 to integral arm portions v67 and 68 to be joined by a band-like stop element 6 9 of further reduced thickness as shown in Fig. 4.

Brackets 59 and 5l provide pivotal support for a permanent magnet armature 121, preferably of generally right angle ,configuration as shown in Fig. 3. Armature 12.1 is mounted on a pintle 3 5 which yfinds its support `in arms D67 and 68, and is of material of high magnetic retentivity and zrnagnetized, with the arms 36 and 37 thereof forming opposite magnetic poles, as indicated by an N and S, Fig. 3. Armature 121 is permitted `pivotal movement from the position shown in Fig. 3 to a position substantially 90 therefrom as shown in Fig. 5. The limit positions are dened by abutment between a bevelled portion '7b of arm 36 and a bevelledportion '34- of pole portion 32 as shown in Fig. 5, and in the alternate extreme position by abutment between rib like element 72 fixed to the outer surface of arm '36 and band 69 which serves 'as ya stop member. Pivotal movement from vthe positions lmentioned results in the corresponding .pivotal movement of an indicating element 73, fixed to the outer wall of arm 37 on an 'intervening support "74, through the are from the position of alignment with viewing window 128, shown in Fig. 5, to a position of concealment behind opaque member 129 as shown in Fig. 3. The inner surface of armature 121 provides support, at a position adjacent the pivotal point, for an inwardly extending actuating cam comprising, as shown in Fig. 11, a pair of laterally directed wire-like members 42 and 43 eading from 'fixed support portions 4.4- and 4S to extend parallel with the .transverse inner surface of the armature.

Members 42 and-43 are positioned for contacting engagement by a bifurcated member 46 defining paired depression tingers 75 and 76 which extend on opposite sides of core 111, respectively, tensioned by a. pair of depending lingers 77 and 78, also supported by member 46. The fingers 77 and 7 8 are disposed on opposite sides o f core 111 as shown clearly in Fig. 4. Upon vdepression of push. rod 48, as best shown in Fig. 3, iingers 77 and 78 engage base portion 4t) and are tensioned lto .provide rctractile rbias for partial return o f push rod 48 upon release of a depressing force. Upon subsequent electromagnetic return of armature 121 to the position shown in Fig. 5, cam arms l2 and 4 3 lift iingers 76 and 77 to the position shown, and return push rod .48 to a fully retracted position, while pivoting bifurcated member 46, and tensioning arms 77 and 78 outwardly from base 4i) to the position shown, in readiness for subsequent manual retraction of the armature 121 without interfering with magnetic pivoting between the limit positions.

The incorporation of an auxiliary switch, position for actuation by the armature when in one of the limit positions, is shown in Fig. 9.

What is claimed is:

l. In a polarized magneto signaling device adapted for removable pressed t engagement within a holder, the combination including an elongate electromagnet including a core, a .coil applied over said core, a skeleton type electrically conducting frame fixed to one end of said core and extending the length of said coil, said frame including portions of U coniguration disposed in both vertical and horizontal planes to provide interrupted sur faces defining four sides of a rectangle as viewed in cross section, a pair of electrically conducting spaced brackets supported by said coil to extend beyond one end of said core and spaced to permit pressed fit engagement of a U portion of said frame therewith, a permanent magnet armature having a pair of L shaped arms pivotally supported at vits midpoint between said brackets for movement to and from said core, different ones of said arms adapted to be aligned substantially parallel with said core in the operated and unoperated position of said armature, respectively, `a plunger slidably associated with said frame, a cam carried by said armature, and cam depressing means cooperatively connecting said plunger and said cam vfor pivotal movement of said armature in response to depression of said plunger.

2. in a ydevice of the character described, the subcombination comprising an electro-magnet including a straight core of low magnetic retentivity material, a permarient magnet armature having a right angular configuration, means pivotally mounting said armature adjacent an end ,of said core for alternate movement or' end portions thereof to and from said core, alternate of said end portions adapted to be aligned substantially parallel with and in close proximity to diametrically opposite portions of the ,end of said vcore in the operated and unoperated position of said armature, respectively, a cam element fixed to said armature to project therefrom, a cam actuating element pivotally mounted laterally of said core and including a finger disposed for-pivotal contacting engagement with said cam element, a -resilient biasing element, stop means restricting pivotal movement of said :biasing .element in `one direction, and a push rod positioned for engagement with said cam actuating element to etect pivoting thereof, upon depression of said rod, whereby said finger pivots said cam and the associated armature in a direction to pivot biasing member into tensioned engagement with said stop means to aid retraction of said nger and push rod upon relief of a rod depression force.

3. A magnetic device having in combination, an electromagnet including a straight core of material having low magnetic retentivity, a permanent magnet armature mounted within the projected cross-sectional area of said core, means pivoting said armature substantially at its midpoint for movement within the eld of magnetic influence of said electromagnet to and from said core, dilerent ends of diametric portions of an end of said armature being aligned substantially parallel with said core in the operated and unoperated positions thereof respectively, said pivoting means being spaced from said core at a distance substantially equal to the distance between one end of said armature to the pivotal point thereof, said diametric portions of said core and said armature each having a complementary shaped end, one of said ends adapted to abut in the operated position of said armature.

4. A magnetic device as claimed in claim 3, wherein said armature comprises a pair of arm portions each at a right angle to the other and extending outward equidistantly from said pivoting means.

5. A magnetic device as claimed in claim 3, further comprising an indicating element cooperatively associated with said armature for indicating the positions of said armature and manually operable means for restoring said armature to its unoperated position, said manual means iixed with respect to said armature.

6. A magnetic device as claimed in claim 3, wherein said armature comprises a pair of like arm portions disposed to each other at an angle of substantially 90, and fixed stop means adapted to abut said armature in the unoperated position thereof, said xed stop means and the end of said core adapted to dene the arc of travel of said armature between its operated and unoperated positions.

7. The device as claimed in claim 5 wherein said restoring means comprises a cam element xed to said armature, a plunger slidably supported in spaced relation to said armature, and a pivotally mounted cam depressing element having a portion disposed within the path of movement of said plunger.

8. The device as claimed in claim 3 wherein said electromagnet comprises a. core having an exposed portion and a portion overed by an excitation winding, said exposed portion being provided with a slot to dene spaced diametrically opposed portions to serves as poles for said ciectromagnet.

References Cited in the file of this patent UNITED STATES PATENTS 420,422 Warner Jan. 28, 1890 492,519 Hard Feb. 28, 1893 574,045 Scribner Dec. 29, 1896 698,027 Knapp Apr. 22, 1902 995,646 Willis June 20, 1911 1,402,305 MacFarlane Jan. 3, 1922 1,743,478 Pratt Ian. 14, 1930 2,180,159 Michaels Nov. 14, 1939 2,276,535 Clare et al. Mar. 17, 1942 2,400,262 Quinnell May 14, 1946 2,405,429 Jewell Aug. 6, 1946 2,575,127 Refschneider Nov. 13, 1951 2,635,155 Barr Apr. 14, 1953 FOREIGN PATENTS 52,225 Sweden Dec. 22, 1920 231,953 Switzerland July 17. 1955 

